Tottenham rocked as Defoe ruled out three months
Spurs' fears over the injury the striker suffered in England's European Championship qualifier in Switzerland on Tuesday night were confirmed following consultation with a specialist on Thursday.
It means the 27-year-old could miss all of his club's Champions League group matches, as well as two England internationals.
A statement on Spurs' official website read: "Following a review by an ankle specialist, Jermain Defoe underwent surgery to repair torn ligaments in his right ankle yesterday evening.
"The striker was forced off with the injury during England's European Championship qualifier in Switzerland on Tuesday and has been ruled out of action for around three months."